1. Field of the Invention
Methods and apparatuses consistent with the present invention relate to wireless communications, and more particularly, to wireless communications that support a high-rate data transmission.
2. Description of the Related Art
The demand for the transmission of mass multimedia data in a wireless network has increased, and there is a greater need for research which would result in an effective transmission method in a wireless network environment. Additionally, the need for the wireless transmission of high-quality video, such as a digital video disk (DVD) video, a high definition television (HDTV) video, or the like, among various home devices, has increased.
Presently, an IEEE 802.15.3c task group is considering a technical standard for transmitting mass data in a wireless home network. This standard, called Millimeter Wave (mmWave), uses an electric wave having a physical wavelength of several millimeters to transmit of the mass data (that is, an electric wave having a frequency of 30 GHz to 300 GHz). In the related art, this frequency band is an unlicensed band and has limited use, for example, in communication carriers, radio astronomy, or vehicle anti-collision.
In the IEEE 802.11b standard or the IEEE 802.11g standard, a carrier frequency is 2.4 GHz, and a channel bandwidth is about 20 MHz. Further, in the IEEE 802.1a standard or the IEEE 802.11n standard, a carrier frequency is 5 GHz, and a channel bandwidth is about 20 MHz. In contrast, in the mmWave, a carrier frequency of 60 GHz is used, and a channel bandwidth is about 0.5 to 2.5 GHz. Accordingly, it can be seen that the mmWave uses a larger carrier frequency and channel bandwidth than the existing IEEE 802.11 standards. Accordingly, if a high-frequency signal having a wavelength in millimeters (Millimeter Wave) is used, a high transmission rate of several Gbps can be obtained, and the size of an antenna can be set to be not more than 1.5 mm. A single chip including the antenna can then be implemented.
In recent years, the transmission of uncompressed audio and/or video (A/V) data between wireless apparatuses using a high bandwidth of the millimeter wave has been studied. Compressed A/V data is compressed with a partial loss through processes, such as motion compensation, discrete cosine transform (DCT) conversion, quantization, variable length coding, and the like, such that portions insensitive to the sense of sight or the sense of hearing of a human being are eliminated. Accordingly, in the case of the compressed A/V data, deterioration in image quality due to a compression loss may occur. Further, A/V data compression and decompression of the transmitting device and the receiving device should follow the same standard. In contrast, uncompressed A/V data includes digital values (for example, R, G, and B components) representing pixel components as they are. Accordingly, in the case of uncompressed A/V data, vivid image quality can be provided.
As described above, since a large amount of data is transmitted in the high frequency wireless communication band, it is important to reduce the waste of wireless resources. Accordingly, there is a need for a technique that supports a high-rate data transmission more efficiently in the high frequency wireless communication band.